Police in Ontario, California were forced to shoot a man at a Stater Bros grocery store as he roamed the aisles armed with a shotgun.

The call came in at approximately 9:45 p.m. Sunday from employees who reported an armed man had entered the 1949 E. 4th Street store and was walking through the aisles.

Authorities said store employees sent out a silent panic alarm after spotting the suspect, who was later identified by authorities as 36-year-old William Baker. After officers arrived at the scene, employees and customers were evacuated from the building, authorities said.

Ontario police said officers entered the store thinking it was an active shooter situation. When they made contact with Baker, officers shot and struck him, but it was not known how many shots were fired.

“There were multiple calls and we also received a silent alarm activation from employees inside the store,” said Det. Melissa Ramirez with the Ontario Police Department. “There were a group of officers who made entry into the store and were treating it very much similar to an active shooter or potential active shooter incident because we were not sure of his motivation behind carrying a shotgun.”

Baker, who ultimately died as a result of his injuries, had not pointed his weapon or shot at anyone, although the gun was in his hands at the time police shot and killed him. California is not an open carry state.

Authorities continue to investigate what drove him to his actions that ultimately lead to his death.